Product and process for rubber compounding



Patented Jan. 14, 1930 UNITED STATES; PATENT oFFicE An'rmrn B. OOWDEBY, ornnnimm, MASSACHUSETTS, AssIcnon ro THE BARRETT comm, A oonrom'rron or new sense PRODUCT AND PROCESS FOR RUBBER COMPOUNDING Io Drawing.

This invention relates to a product espe-, ciall suitable for rubber compounding and to t e process of making compounds con and a speci c gravity of approximately 1.30 to 1.35, and is entirely free from 011 and' moisture. This sort of distillation may be carried out for example, by recirculating a neutral gas through the tar While it is being distilled and r moving the volatile materials from the gas after it leaves the tar and before re-entets the tar as described in l1 S,

Patent No, lell fiilfia The product containing this very hi h per of ea c n of the sort mentioned above insoluble in benzol, and consisting for the most part ielting point hydrocarbons is or pulverized in any convenient will pass through 00 meshes to the inch, oerticles capable passing b and consistin oi by Weight or car ve to 40 parts i u oi; very liege finely grou in the usual way b oer later: othe between smooth roll 0 mean ole p a I lrocerbons are thee.

Application filed November 22, 1924. Serial no. 751,ss7.

carbons which become temperatures. v a

- Heretofore lam black or carbon has been produced for rub er compounding by burning natural gas, oils, or other hydrocarbons in an insufiicient suppl of air and permitting the products of com ustion to impinge upon a cold surface from which the carbon may be subsequently removed. Such carbon is very flufiy and light and has a marked tendency to fly around in the air when disturbed. It is very different from the present product that does not result from coolin gaseous or light products of combustion. %he present product is a residue left after distilling ofi volatile products from coal tar in such a manner as to give a product containing an exceedingly high percentage of uncombined carbon. The carbon seems to be a colloidal sus ension in the remaining hydrocarbons oil igh melting point that are themselves quite brittle cold, Many other carbons of the prior art stii'len the batches used for plastic at: elevated .making rubber products to such a great ex tent that the practical quantity that can be used is limited, the other hand the pres ent product is very soft cerbonand greater quantities can "if many stoelrs, are not permissib pigment power 0 H I ll lg tendency W the oori oil. the inven= tion very much less pigment strength'anol can be used, example, in appreciable quantities, say u to by Weight, in the manufacture colored heels and soles discoloration.

' ative of this in "vention, i may eta a o cool tar containlarge auto t, say about one-filth by Weight, of uncombined or matter insoluble i. hot b ol 'oluol distill the same for sever l hours, distillation be aecompan y the recirculation of a neutral carbon dioxide, tor example, until at 60 750% by weight of volatile s been removed so that the residue will u Lein approximately by Weight of insoluble l). hot benzol or l the most is a speci Ml the 110 ti let) part high boiling h drocarbon com ounds. This residue is with rawn and permitted to cool whereupon it becomes a very brittle roduct. It can then be ground or pulvermod to a very fine state and the particles which are fine enough to pass through a 200 mesh screen are to be used in rubber oompounding. This finely ground material is mixed with the rubber stock together with other fillers, if desired, and incorporated therein in the regular manner after which the mixture is vulcanized.

The term uncombined carbon as used in the specification and claimsrefers particularly, as hereinbefore indicated, to material insoluble in benzol, the amount of which pres ent in the coal tar residue may be determined for example by the method set forth on pages 736 and 820 (test D5) vol. 10 (1918) of the Journal of Industrial & Engineering Chemistry.

I claim:

I 1. In the process of compounding with rubber, the step which comprises mixing rubber stock and a coal tar distillation'residue containing about 60% of uncombined car-' bon.

2. In the process of compounding with rubber, the stepwhich comprises mixing rubmelting point h drocarbons, said residue bein obtainable y a coal tardistillation invo vin the circulation of an inert gas throug the tar and having a specific gravity of approximately 1.30 to 1.35 and being substantially free from oil and moisture.-

9. A composition comprising rubber compounded with a coal tar residue contaim'n about 60% of benzol-insoluble material an gbout 40% of high melting point hydrocarons.

10. A'composition comprisin rubber compounded .with a coal tar resi ue having a melting point above 350 F. and containing about 60% benzol-insoluble material and about 40% high melting point hydrocarbons.

11. A composition comprising rubber compounded with a coal tar residue having a melting point above 350 F.

, In testimony whereof I aifix my signature.

ARTHUR B. GOWDERY.

pounded with uncombined carbon and high melting point hydrocarbons, said carbon and said hydrocarbons being in the proportion of about 3 to 2. V

4. A composition comprising rubber com-- pounded with a coal tar residue containing uncombined carbon and high melting point hydrocarbons, said carbon and said hydrocarbons being in the proportion of about 3 to 2.

5. A composition comprising rubber com pounded with a coal tar residue containing about 60% of nncombined carbon and about 40% of high melting point hydrocarbons,

said residue being incorporated with said rubher in the form of particles small enough to pass through a 200 mesh screen.

6. A composition comprisin rubber compounded with a coal tar resi ue containing about 60% uncombined carbon and about 40% of high melting point hydrocarbons, said residue being present in amounts not exceeding about 15%.

7. A composition comprising rubber compounded with a coal tar residue comprising about 60% uncombined carbon and about 40% of high melting point hydrocarbons, said rubber being in excess of said coal tar residue. r

8. A composition comprising rubber com pounded with a coal tar residue containing uncombined carbon disseminated in high: 

